SEOUL (Reuters) - Three drones that crashed in South Korea had onboard flight programming that showed they were launched from North Korea and were meant to return after flying over military installations in the South, the defence ministry in Seoul said on Thursday.

South Korean and U.S. officials jointly examined the three drones that were recovered in three different locations near the Korean border over a two-week period starting in late March.

The second was discovered soon after a three-hour artillery barrage between North and South Korea in waters near a disputed maritime border.

The drones' penetration of South Korean airspace raised questions about its air defence capabilities while Pyongyang clings to its hard-line stance against Seoul.

"North Korea's action is a clear military provocation that violates the armistice and the South-North non-aggression agreement," the South's defence ministry said in a statement.

Pyongyang has denied any involvement, calling the South's charge a fabrication.

In April, North Korea proposed a joint probe with the South but Seoul rejected the proposal.

South Korea's defence ministry also said in April some of the parts in the recovered drones were manufactured in China, Japan, the Czech Republic and the United States, but it offered no further details.

Photographs unearthed by the North Korea Tech blog showed a drone made by a Chinese company with an almost identical size and shape to some of the drones found in South Korea.

South Korea's defence ministry said it was aware of the Chinese-made drone and had sought explanations from the Chinese government.

Repeated calls by Reuters to Taiyuan Hangyou Hangkong Technology Co. Ltd, the company that produces the drones, were not answered.

Chin's foreign ministry also did not respond immediately to requests for comment.

So far this year North Korea has test-fired medium-range ballistic missiles, threatened to conduct a nuclear test, and fired more than 500 artillery shells that landed in disputed waters between the two Koreas.

Pyongyang has also recently conducted engine tests for an intercontinental ballistic missile that could potentially deliver a nuclear warhead to the United States, a U.S. think tank said on Friday.

North Korea released TV footage last year of practice drones which had been modified to crash into predetermined targets, but it is not believed to operate drones capable of air strikes or long-range surveillance sorties.

North Korea's state media said last year leader Kim Jong Un had supervised a drill of "super-precision" drone attacks on a simulated South Korean target.

Although the North has one of the world's largest standing armies, much of its equipment consists of antiquated Soviet-era designs. It has focused its resources on developing nuclear and long-range missile programmes.

(Additional reporting by James Pearson and Lim Sang-gyu in SEOUL and Ben Blanchard in BEIJING; Editing by Jack Kim and Paul Tait)

BEIJING (Reuters) - Chinese authorities have detained an outspoken journalist and political activist accused of providing state secrets to foreign contacts, the official Xinhua News Agency said on Thursday, and state television aired images of her making a confession.

The arrest of journalist Gao Yu is the latest in a string of detentions that critics say shows Chinese leaders' sensitivity to dissent ahead of the 25th anniversary of a crackdown on a pro-democracy movement around Beijing's Tiananmen Square on June 4, 1989.

Gao, who previously worked for state media, was a prominent supporter of the pro-democracy protests in 1989. She was jailed in 1993 for six years on charges of divulging state secrets.

On Thursday morning, the official China Central Television showed Gao, with her face blurred out, confessing.

"I believe what I have done has violated the law and has harmed the interests of (my) country," Gao said. "What I have done is extremely wrong. I will earnestly and sincerely take a lesson from this, and I admit my guilt."

Gao is accused of illegally obtaining a highly confidential document and sending an electronic copy of it to a website abroad in June last year, Xinhua said, citing a police statement.

She was detained on April 24, Xinhua said. Gao's friends became concerned after she missed a low-key gathering of activists late last month to commemorate a key event in the lead up to the Tiananmen Square crackdown.

A prominent free-speech lawyer, Pu Zhiqiang, was also among those detained earlier.

The Committee to Protect Journalists, in a statement on April 28, noted that Gao's detention was part of a pattern.

"It has been a government tradition to start cracking down on protesters, critics, and dissidents before April 15, and this year is no different," the statement said.

JOHANNESBURG (Reuters) - South Africa's ruling African National Congress (ANC) held an early lead as votes were counted on Thursday, a day after millions cast their ballots in the country's first "Born Free" election.

The ANC, the liberation party that swept to power under the leadership of Nelson Mandela at the end of apartheid in 1994, had 55.8 percent of the vote after the results from nearly 20 percent of polling stations had been counted, the electoral commission said.

The ANC's nearest rival, the Democratic Alliance, held 31 percent as it looks to make up more ground after polling 16.7 percent nationwide at the last general election in 2009.